The use of cans such as pull-tab quick opening metal sealed containers has been fast growing for some decades because of their efficacy.
Moreover, the manufacture of said cans is implemented by now and it follows general processes that have found both the acceptance by customers and acceptable packaging costs.
The use of metal instead of plastic polymers for making said containers, among other things, allows a particularly environmentally-friendly recycling of the base material unlike the containers made of plastic materials.
In time, however, sanitary problems have arisen that currently are still unsolved, particularly those related to the opening of the cans. The simple fact of pouring the beverage in a glass from a torn opening whose outer surface may have been contaminated formerly, or even worse the fact of drinking directly from the torn opening can result in severe oral or gastrointestinal infections.
In the last years, contaminations of the external surfaces of cans have taken place due to various microbial strains and particularly contaminations by microbial strains of leptospirosis, probably occurred during the storage of the cans in unhygienic rooms, especially under hot climates and in the possible presence of rats.